1. Field of the Invention
The present invention relates to an image pickup apparatus for converting images recorded on a film such as a movie film into video signals.
2. Description of the Related Art
Conventionally, a telecine apparatus is known as an apparatus for converting images recorded on a movie film into video signals. There are two types of telecine apparatuses. One type is of feeding a movie film continuously. The other type is of feeding a movie film intermittently. For example, in an intermittent feeding type telecine apparatus, a movie film is fed frame by frame intermittently. One frame of the images recorded on the movie film is positioned on an optical axis of a lens of a camera part. Light from a light source is irradiated to the movie film to cause light transmitted therethrough to be incident on a video part. One frame of the images recorded on the movie film is picked up by the video part. After picking up one frame of the images, the movie film is fed and the next frame is positioned in the optical axis of the lens, and the same image pickup as set forth above is repeated. In such a telecine appratus, process of converting images recorded on a movie film into video signals is performed in real time for example by moving the movie film by 24 frames per second.
In the telecine apparatus described above, as an image pickup means in the camera part, an image pickup device such as a CCD (charge coupled device) is utilized. In such case, resolution of video signals obtained therethrough is limited by the number of pixels in the image pickup device.
In recent years, in the field of movie production, image processing is performed after converting images recorded on a film into video signals. In this field, high resolution and high picture quality are also required for video signals obtained from images recorded on a film. For this task, the number of pixels in CCD is not sufficient. Therefore, a telecine apparatus has a problem that it is also insufficient in resolution to be used for movie production which requires high resolution.
On the other hand, in the field of movie production described above or the like which requires high resolution and high picture quality, as an apparatus for converting images recorded on a movie film to video signals, a super high picture quality image pickup device called film scanner is utilized. In the film scanner, different from telecine apparatus, process of converting images recorded on a movie film into video signals is not performed in real time, but rather, by spending a sufficiently longer time.
However, a film scanner has a problem that it is expensive in particular in image pickup system in order to realize super high picture quality. Also, in a film scanner, of course, it is impossible to convert images recorded on a movie film into video signals in real time as in a telecine apparatus.
Therefore, there is a problem that those who sometimes want to convert pictures recorded on a movie film into video signals in real time and sometimes want to convert pictures recorded on a movie film into video signals with high resolution must provide both telecine apparatus and expensive film scanner.